1. Field of the Invention
The present invention relates to an endoscope insertion portion, in particular, an endoscope insertion portion wherein an image pick-up assembly for picking up an observation image and a channel assembly used for an insertion of an accessory and the like are inserted through the endoscope insertion portion in the axial direction from the distal end portion to the proximal end side.
2. Description of the Related Art
In Jpn. Pat. Appln. KOKAI Publication No. 8-299258, an endoscope is disclosed. The endoscope includes an elongated insertion portion configured to be inserted into a cavity. A distal end rigid portion is formed on the distal end portion of the insertion portion. An image pick-up unit for picking up an observation image is provided in the distal end rigid portion. In the image pick-up unit, an objective optical system, an image pick-up device and an image pick-up board are provided in order from the distal end side to the proximal end side, and an image pick-up cable is extended from the proximal end portion of the image pick-up unit. The image pick-up unit and the image pick-up cable forms an image pick-up assembly. Moreover, a channel pipe is provided in the distal end rigid portion. The distal end portion of a channel tube is fitted onto and fixed to the proximal end side part of the channel pipe, and the channel tube is extended from the channel pipe. The channel pipe and the channel tube forms a channel assembly used for an insertion of an accessory and so on. The above image pick-up assembly and the channel assembly extend in the axial direction from the distal end portion to the proximal end side and arranged side by side in the endoscope insertion portion.